Apple's iOS and Microsoft's Windows Phone
operating system have grown faster than Android has over the past year.

That's according to researchers at Kantar
Worldpanel ComTech, who say smartphone sales as a whole have remained
relatively stable this year compared to 2012. In terms of market share, iOS is
up 2.3 percentage points, Windows is up 1.8 percent and Android is up just 1.4
percent, year over year.

Through the three-month period ending on April 30, Kantar says Android now
owns more than half (51.7 percent) of the smartphone sales market; iOS remains
in second place with 41.4 percent of smartphone sales; and Windows’ smartphone
sales share is 5.6 percent.

Among U.S. carriers, Verizon is the leader in smartphone sales, with 36.3
percent of the market; AT&T is second with 26.3 percent; followed by
Sprint's 13.1 percent and T-Mobile's 11.3 percent (which was the only carrier
to see its share fall).

“Verizon and Sprint’s slight increase is thanks to the growth of two key
players," said Kantar Worldpanel ComTech analyst Mary-Ann Parlato.
"For Verizon, Windows’ share rose from 0.2 percent in the three months
ending April 2012 to 6.8 percent by the period ending April 2013. At Sprint,
they continued to reap share increases thanks to theiOS offering – iOS sales
share on Sprint grew from 33.4 percent to 38.4 percent over the last year."

Of those who purchased a Windows device in the last year, 42 percent came
from a feature phone, 25 percent from another Windows device and 23 percent
from Android. While iOS is similarly effective at capturing Android users and
their own users, only 31 percent came from a feature phone device, showcasing
Windows strength in attracting feature-phone users, the study revealed.